Detecting the Effect of Melatonin Against Deltamethrin-Induced Neurotoxicity Using Adult Male Rats Model

Background and Objectives: Deltamethrin (Delta), a widely used insecticide, is associated with neurotoxic effects primarily due to its ability to induce oxidative stress. To date, no specific antidote is available for deltamethrin poisoning. This study aimed to investigate the potential protective effects of melatonin, a potent antioxidant, against deltamethrin-induced neurotoxicity. Methods: The median lethal dose (LD₅₀) of deltamethrin was determined to be 106.6 mg/kg (p.o.) in adult male rats. Twenty rats were divided into four groups (n = 5 per group): Group A received deltamethrin alone (75 mg/kg, p.o.); Group B was pretreated with melatonin (12.5 mg/kg, i.p.) 15 minutes prior to deltamethrin administration; Groups C and D received melatonin alone and distilled water, respectively. Neurotoxic signs, onset time, and toxicity scores were recorded, and antioxidant enzyme (glutathione peroxidase) levels were measured. Results: Rats treated with deltamethrin alone exhibited severe neurotoxic signs within 55 ± 0.7 seconds, with a toxicity score of 24. Pretreatment with melatonin significantly delayed the onset of neurotoxicity (720 ± 0.2 seconds) and reduced the overall toxicity score to 4. This group also showed a marked decrease in the incidence of individual neurotoxic signs and a significant increase in serum glutathione peroxidase levels compared to the deltamethrin-only group. Conclusion: Melatonin demonstrated a protective effect against deltamethrin-induced neurotoxicity, likely due to its potent antioxidant properties. These findings suggest the potential use of melatonin as a therapeutic agent in managing insecticide-induced oxidative stress and neurotoxicity.